Forming fully rounded corners on sheet metal furniture



Oct. 10, 1933. R. v, HEDLUND FORMING FULLY ROUNDED CORNERS ON SHEETMETAL FURNITURE Filed July 29, 1932 2 Sheets-Sheet 1 ATTORNEY Oct. 10,1933. R. v. HEDLUND FORMING FULLY ROUNDED CORNERS ON SHEET METALFURNITURE Filed July 29, 1932 2 Sheets-Sheet 2 ATTORNEY Patented10,1933. 1

UNITED STATES;

PATENT OFFICE FORMING FULLY ROUNDED CORNERS ON SHEET METAL FURNITURE Myinvention relates primarily to kitchen equipment such as tables, sinksand the like and more particularly to the formation of such articleswhen made of sheet metal. The relatively recent increase in generalknowledge regarding the cleanliness necessary during the preparation andcare of food has caused metal to replace wood in the construction ofsuch equipment. A

non-corrodible metal, such as monel, is especially desirable for suchpurposes 'as it will also take a high degree of polish.

The top of av good wooden kitchen table is smoothed off at the edges andthe corners rounded not only for appearance sake but more especially forsafety against injury to the kitchen operative due to accidentalcontact. At first, a sheet metal table top was. formed with sharpcorners constructed by cutting a piece of metal from each corner,bending adjacent edges at an angle to the surface until the cut metaledges came into contact and then welding them together. The rough spotswere then ground ofi and polished, but the result was a mitred corner,

a sharp corner, which is far more dangerous to bump against than acorner of a wooden table.

Metal kitchen tables and sinks for restaurants, hospitals and hotels areapt to be relatively large, sized to supply the demands of the patronsand of a variety of shapes to provide an economy of floor space.Generally they are made to lit a certain spot in a room and it is seldomthat two architects design two kitchens of the same size and shape.Therefore, such equipment cannot be made on a production basis but hasto be built up by the processes possible with the tools of the tinsmith.

I have invented a new, novel and relatively inexpensive method of makingfully rounded corners on a metal top table or a sink which adds to itsbeauty, renders it more easily cleanable and presents smoothly curvedand relatively large areas for accidental contact, tending to diminishinjury to both person and building. The appearance of such equipmentalso renders them more supported on a stiff frame, are made of non--corrodible metal of approximately an eighth of an inch thickness andcommonly the edges are formed or rolled to a curve cylindrical in shapeand of a diameter of about two inches. This'calls for a cutting away ofthe metal at the corners before the edges are rolled and later weldingin corners which have been formed to the required shape. My invention'is especially applicable to the requirements of such conditions.

easily salable. Such table tops, which are usually.

in the appearance shown in Figs. 2 and 3.

The making of a sink requires much the same procedure as does a tablebut with the addition of extra welded-in pieces for the bottom corners.Sinks for the kitchens of large institutions are long and often have toconform to the shape of 0 the room. Thus they are .specials and, ofnecessity, are made up by the tools of a well equipt tinsmith shop. I Myinvention allows smoothly rounded corners to be formed on such sinksthus adding materially to cleanliness and to the safety 5 from injury tothe kitchen operatives.

The drawings illustrate he application of my invention to two types ofcorner.

Fig. 1 is a plan view of a table top showing the fully rounded corners;

Fig. 2 is a front elevation of Fig. 1, being partly broken away on lineA-A;

Fig. 3 is a perspective view of a table top with the edges rolled overand ready for the welding-in of the segment of the spherical-like shell;

Fig. 4 is a full size plan view of the blank before being drawn to itsspherical segment shape;

Fig. 5 is a perspective view of the piece shown in Fig. 4 after beingdrawn so that its surface becomes substantially spherical;

Fig. 6 is a plan view of the three blanks used to form the major portionof a sink;

Fig. 7 is an end elevation illustrating the first bends in theconstruction of a sink;

Fig. 8 is a perspective view of my method of constructing a sink andshowing an end weldedin;

Fig. 9 is a plan view of the blank, before drawing, for the upper corneron the sink;

Fig. 10 is a plan view of the blank, before drawing, for the lowercorner on the sink;

Fig. 11 is a perspective inside view of one of the end pieces for mysink, and

Fig. 12 is a perspective View of my sink showing the fully roundedcorners.

The odd-shaped table top 1 shown in Fig. 1 is characteristic of the typeoften encountered in special work. After the proper-sized pieces havebeen cut out of the corners, the flat metal is rolled over in thewell-known manner resulting I prefer to roll the edges over so that theyterminate in a plane 2 parallel with the table top proper. A good way isto turn the lower edges under no further thanshown in Fig. 3, though bymy improved method I can, if desired, carry the lower edges into theplane above referred to and as indicated at 3 in Fig. 2. To fill in theholes 4 at the corners I generally employ blanks 5 which are drawn undera press so that the surface of the blank becomes spherical, orsubstantially so, as shown at 6 in the perspective view Fig. 5. Thesespherical-like shells are then welded into the holes 4 at the corners,or attached in some other good manner and after the joints have beenground evenly and the metal polished the appearance is extremelypleasing to the eye as the joint is quite invisible with the seamseliminated. Such corners may then be characterized as comparable to thesurface of revolution about a desired axis of the curved edges leadingthereto.

It is obvious that by the use of my novel method I can carry twoopposing edges around and underneath until they meet under the center ofthe table. When this joint is welded up and the corner pieces put in Iwould have a completely enclosed integral table top with fully roundedcorners and a top and bottom consisting of smooth, plane surfaces.

One good method of forming the sink '7 shown in Fig. 12 is to cut outtwo end pieces 8 and 9 and body portion 10 which is then rolled and bentto the shape 11 shown in Fig. '1. The end pieces 8 and 9 are rolled sothat each becomes as shown like 12 in Fig. 11 after which they arewelded to the body portion as shown clearly in Fig. 8. If preferred, theinturned edges which appear on end pieces 12 in Fig. 11 may be omittedthereon, being formed instead on the main body portion 10. The sink isnow complete except for filling in the holes 13 at the top corners andthe smaller holes 14 at the bottom corners. I accomplish this by thesame general idea as previously outlined in describing the table top, byutilizing blanks 15 and 16 of the proper shapes which will,

4 after drawing, be welded into holes 13 and 14 and present the, fullyrounded edges so much desired onthis type of kitchen furniture.

It is well known that heavy forming and drawing presses are economicalto use in quantity production. However, as the diameter of a rolled edgeincreases in proportion to the thickness of the metal from which it ismade the difficulty of compressing the metal on the extreme inner edgeof a curved corner, something similar to that shown at 3 in Fig. 2,constantly becomes more difficult, or even to approximate such shapes.On the other hand there is practically no limit to such sizes in myclass of work, but I prefer to limit myself to a minimum diameter of therolled edge of eight times the thickness of the metal in order that theedge may appear in proportion to the size of the furniture. The rolledover edge can be nearly a full cylinder or be less than a half cylinder,as desired, because of the use of my invention. It is apparent that mynovel system herein set forth is especially well adapted for thetinsmith both as regards beauty, utility and economy in manufacture.

It is to be understood that the particular embodiments of the inventiondisclosed herein are of an illustrative character and are notrestrictive, and that various changes in form, construction andarrangement of parts may be made within the spirit and scope of thefollowing claims.

Having thus described the invention, what is claimed as n :w, anddesired to be secured by Letters Patent, is:

1. The method of forming a fully rounded corner on a table top, sink orthe like made from sheet metal and having its edges shaped toapproximate sectors of cylinders which consists in. fitt'ng a sector ofa substantially spherical shell into each corner and welding it in placewhereby the contour of the corner becomes substantially thesurface ofrevolution about a desired axis of the contour of the cylindrical-likeedge.

2. The method of forming a fully rounded corner on a table top, sink orthe like-made from sheet metal and having rolled over edges compr. singthe step outlined in claim 1 together with smoothing off the roughplaces resulting from the fitting and welding and polishing the corner.

3. The method of making a sheet metal article having plane and curvedsurfaces which consists in forming the areas which are surfaces ofrevolut'on of a straight line entirely on one piece of plane, sheetmetal, forming those areas which are surfaces of revolution of curvedlines entirely from other pieces of sheet metal and welding the edges ofthe several pieces together to form one continuous surface of thedesired shape.

4. The method of making a. sheet metal sink which consists in preparinga sheet of metal for constructing the main or central portion of thesink, rolling the longitudinal edges into cylindrical-like shape,bending parallel port'ons of the sheet upwards to form respectively thefront and. back of the sink with easilycleanable curves at the bends,preparing two sheets of metal shaped for the two ends of the sink,bending the bottom portion of each end piece in well rounded curves tojoin the bottom portion of the main sheet and s'milarly bending thefront and back portions of the ends to join the front and back sides ofthe main portion of the sink, bending the tops of the ends intocylindrical-like shape comparable to the rolled longitudinal edges ofthe main portion, welding the ends onto the man body at the bottom andsides, fitting and welding smoothly rounded pieces of formed sheet metalinto the lower and upper corners, removing the rough spots and polishingthe ensemble whereby is formed a sheet metal sink with fully roundedcurves at top, bottom and corners.

5. The method of making a table top, sink or the like, formed from sheetmetal and hav'ng two or more adjacent edges shaped to approximatesegments of cylinders, which consists in fitting a segment of aspherical-like shell into the corner space bounded by two of saidadjacent edges and welding it into place.

6. The method of making a table top, sink or the like, as specified inclaim 5 together with smoothing. off the rough places resulting from thefitting and welding, and thereafter polishing the corner.

RALPH VICTOR HEDLUND.

